Lecture 7 Flashcards
1
Q
Lymphocytes (T-Cells, B-Cells, and Natural Killer Cells)
A
- T-Cells: Cell-mediate Adaptive Immunity
- B-Cells: Humoral Adaptive Immunity
- NK Cells: Innate Immunity
2
Q
Lymphocytes
A
- Cluster of differentiation marker
—- Abs - Distinct CD proteins are differentially expressed in different
- lymphocyte sub-populations as they undergo their lineage-specific differentiation
3
Q
B-Cells (Antibody-producing Lymphocytes)
A
- Originally discovered in the Bursa of Fabricius in chicken
4
Q
B-Cells
A
- Humans: B-Cells mature in the bone marrow
- Part of the Adaptive Immune System
- express B-Cell Receptors (BCR) on their surface
— membrane-bound antibody
— >100,000 BCR protein copies/B-cell
— each individual B-Cell has a unique BCR clone
— cam recognize soluble or particulate antigens
5
Q
B-Cells
A
- Naïve B-Cells: Antigen Binding to BCR
— results in plasma cells - Plasma Cells: Increased ‘protein production’ organelles
6
Q
T-Cells (Cell-Mediated Immunity)
A
- Site of T-Cell maturation: Thymus
- Part of the Adaptive Immune System
- Express T-Cell Receptors (TCR) on their surface
— each individual T-Cell has a unique TCR clone
—- only recognize antigens presented on MHC proteins - Two major T-Cell types:
a. T helper cells (TH)
b. T cytotoxic cells (Tc)
7
Q
Educating Naïve TC-Cells
A
- Requires Antigen Presenting Cell
- TCR binds to MHC-antigen complex
- Binding induces clonal proliferation
- Binding induces differentiation cytotoxic T lymphocyte (CTL)
8
Q
Natural Killer Cells
A
- Lytic Granules present in the cytoplasm
- Originates from Lymphoid precursors
- Part of the Innate Immune System
- Detects and Targets “Abnormal” Cells
a. Tumor Cells
b. Virally-infected
9
Q
Natural Killer Cells: Absence of MHC Class 1
A
- ‘Normal’ Cells: MHC I on their surface
- NK Cells MHC I recognition: inhibits cytotoxic granule release
- Lack of MHC I recognition: permissive for cytotoxic granule release
